Study: Habitat 'clusters' could save birds

ITHACA, N.Y., Feb. 22 (UPI) -- U.S. researchers say providing a close network of suitable habitats can improve the long-term survival of an endangered Florida bird species.

Scientists at Cornell University in New York state say "clustered habitat networks" separated by no more than 2 or 3 miles are needed to maintain the genetic diversity of Florida Scrub-Jays, a species at risk of extinction with roughly 5,000 birds left in the world.

The study has found a direct connection between genetic variation of Florida Scrub-Jay groups and the geographic distances separating patches of their favored scrub-oak habitat, Cornell researchers said in a release Wednesday.

When habitat patches are separated by more than 2 to 3 miles, the distance is too far to permit free interbreeding. That results in more inbreeding within isolated groups that reduces genetic fitness, increasing the change an isolated population will die out.

"We now know how to configure the stepping stones of scrub-oak habitat so they can link together Florida Scrub-Jay populations and maintain sufficient genetic diversity to promote long-term survival of the species," John Fitzpatrick, executive director of The Cornell Lab of Ornithology, said.

The findings suggest a precise prescription for sustaining fragmented populations of an endangered species and could be a model for other examples around the country, researchers said.

The Florida Scrub-Jay, the only bird found exclusively in Florida, is under threat because the high, dry, sandy scrub-oak patches where the bird lives and breeds exclusively have been prime real estate for Florida developers and for citrus farms, the study found.

Today, only about 5 percent of the original scrub-oak habitat remains, researchers said.